Latent developmental potential to form limb-like skeletal structures in zebrafish.

Changes in appendage structure underlie key transitions in vertebrate evolution. Addition of skeletal elements along the proximal-distal axis facilitated critical transformations, including the fin-to-limb transition that permitted generation of diverse modes of locomotion. Here, we identify zebrafish mutants that form supernumerary long bones in their pectoral fins. These new bones integrate into musculature, form joints, and articulate with neighboring elements. This phenotype is caused by activating mutations in previously unrecognized regulators of appendage patterning, vav2 and waslb, that function in a common pathway. This pathway is required for appendage development across vertebrates, and loss of Wasl in mice causes defects similar to those seen in murine Hox mutants. Concordantly, formation of supernumerary bones requires Hox11 function, and mutations in the vav2/wasl pathway drive enhanced expression of hoxa11b, indicating developmental homology with the forearm. Our findings reveal a latent, limb-like pattern ability in fins that is activated by simple genetic perturbation.

Apical expansion of calvarial osteoblasts and suture patency is dependent on fibronectin cues.

The skull roof, or calvaria, is comprised of interlocking plates of bones that encase the brain. Separating these bones are fibrous sutures that permit growth. Currently, we do not understand the instructions for directional growth of the calvaria, a process which is error-prone and can lead to skeletal deficiencies or premature suture fusion (craniosynostosis, CS). Here, we identify graded expression of fibronectin (FN1) in the mouse embryonic cranial mesenchyme (CM) that precedes the apical expansion of calvaria. Conditional deletion of Fn1 or Wasl leads to diminished frontal bone expansion by altering cell shape and focal actin enrichment, respectively, suggesting defective migration of calvarial progenitors. Interestingly, Fn1 mutants have premature fusion of coronal sutures. Consistently, syndromic forms of CS in humans exhibit dysregulated FN1 expression, and we also find FN1 expression altered in a mouse CS model of Apert syndrome. These data support a model of FN1 as a directional substrate for calvarial osteoblast migration that may be a common mechanism underlying many cranial disorders of disparate genetic etiologies.

An Fgf-Shh positive feedback loop drives growth in developing unpaired fins.

The origin and diversification of appendage types is a central question in vertebrate evolution. Understanding the genetic mechanisms that underlie fin and limb development can reveal relationships between different appendages. Here we demonstrate, using chemical genetics, a mutually agonistic interaction between Fgf and Shh genes in the developing dorsal fin of the channel catfish, Ictalurus punctatus. We also find that Fgf8 and Shh orthologs are expressed in the apical ectodermal ridge and zone of polarizing activity, respectively, in the median fins of representatives from other major vertebrate lineages. These findings demonstrate the importance of this feedback loop in median fins and offer developmental evidence for a median fin-first scenario for vertebrate paired appendage origins.

CHARIOT: a phase I study of berzosertib with chemoradiotherapy in oesophageal and other solid cancers using time to event continual reassessment method.

BACKGROUND: Berzosertib (M6620) is a highly potent (IC50 = 19 nM) and selective, first-in-class ataxia telangiectasia-mutated and Rad3-related protein kinase (ATR) inhibitor. This trial assessed the safety, preliminary efficacy, and tolerance of berzosertib in oesophageal cancer (A1 cohort) with RT and advanced solid tumours (A2 cohort) with cisplatin and capecitabine. METHODS: Single-arm, open-label dose-escalation (Time-to-Event Continual Reassessment Method) trial with 16 patients in A1 and 18 in A2. A1 tested six dose levels of berzosertib with RT (35 Gy over 15 fractions in 3 weeks). RESULTS: No dose-limiting toxicities (DLTs) in A1. Eight grade 3 treatment-related AEs occurred in five patients, with rash being the most common. The highest dose (240 mg/m2) was determined as the recommended phase II dose (RP2D) for A1. Seven DLTs in two patients in A2. The RP2D of berzosertib was 140 mg/m2 once weekly. The most common grade ≥3 treatment-related AEs were neutropenia and thrombocytopenia. No treatment-related deaths were reported. CONCLUSIONS: Berzosertib combined with RT is feasible and well tolerated in oesophageal cancer patients at high palliative doses. Berzosertib with cisplatin and capecitabine was well tolerated in advanced cancer. Further investigation is warranted in a phase 2 setting. CLINICAL TRIALS IDENTIFIER: EU Clinical Trials Register (EudraCT) - 2015-003965-27 ClinicalTrials.gov - NCT03641547.

Cadmium exposure and risk of breast cancer: A meta-analysis.

BACKGROUND: Cadmium is a heavy metal with carcinogenic properties, highly prevalent in industrialized areas worldwide. Prior reviews evaluating whether cadmium influences breast cancer have been inconclusive and not reflected several recent studies. OBJECTIVE: To evaluate the association between cadmium exposure and female breast cancer incidence, with an emphasis on separately estimating dietary vs. airborne vs. biomarker measures of cadmium and studies published until October 2022. METHODS: We evaluated risk of bias using set criteria and excluded one study judged to have high risk based on self-report of breast cancer and insufficient adjustment. We conducted a random effects meta-analysis of epidemiological studies, including subgroups by exposure route and by menopausal status. RESULTS: A total of 17 studies were eligible for our meta-analysis. Only 2 studies addressed airborne cadmium directly. Breast cancer risk was elevated in women exposed to higher levels of cadmium across all studies - pooled odds ratio: 1.13 (95% confidence interval: 1.00, 1.28), with notable heterogeneity between studies (I2 = 77%). When examining separately by exposure route, dietary cadmium was not linked with an elevated risk - (OR: 1.05; 95%CI: 0.91, 1.21; I2 = 69%), consistent with prior reviews, but biomarker-based studies showed an elevated but non-significant pooled measure (OR: 1.37; 95%CI: 0.96, 1.94; I2 = 84%). We did not observe any clear patterns of different risk by menopausal status. CONCLUSION: Findings from our meta-analysis suggest that exposure to higher cadmium increases the risk of breast cancer in women, but with remaining questions about whether non-dietary exposure may be more risky or whether residual confounding by constituents of tobacco smoke may be at play.

Risk of colorectal adenomas and cancer in monoallelic carriers of MUTYH pathogenic variants: a single-centre experience.

PURPOSE: The carrier frequency of MUTYH pathogenic variants in the population may be as high as one in 45. Some studies have found an increased risk of colorectal cancer (CRC) in monoallelic carriers of MUTYH pathogenic variants, but the role of early surveillance colonoscopy is not conclusive. This study aimed to assess the outcomes of colonoscopy surveillance in MUTYH carriers. METHODS: Patients, with a monoallelic pathogenic variant in MUTYH, found at cascade testing, were identified from the St Mark's Hospital Polyposis Registry database. Findings at surveillance colonoscopy were reviewed. RESULTS: Two hundred and forty-nine carriers were identified, of whom 125 had undergone at least one surveillance colonoscopy. Twenty-eight patients (22%) developed at least one adenoma; all adenomas had low-grade dysplasia (LGD). The median age at first colonoscopy was 36 years (range 16-75 years). The median age at first adenoma detection was 43 years (range 22-75 years). The cumulative incidence of adenoma development by age 30, 40, 50, 60 and 70 years was 3.2%, 8.8%, 15.2%, 18.4% and 20.8%, respectively. No CRCs were observed. CONCLUSIONS: Our cohort of monoallelic carriers of MUTYH pathogenic variants is a relatively younger group than adults entering population screening colonoscopy, but a high adenoma rate was not observed. No CRCs were detected, suggesting that current guidance that these individuals should be managed in the same way as the general population is reasonable.

MUTYH-associated polyposis - colorectal phenotype and management.

AIM: The aim was to determine the presentation, management and outcomes of MUTYH-associated polyposis (MAP). METHOD: A prospectively maintained database was used to identify patients with MAP. Demographic data and data on germline mutation, surgical management, histopathology of tumours and endoscopic surveillance were collected. RESULTS: In all, 134 patients with MAP were identified. The majority presented symptomatically (n = 83). Sixty-eight patients developed cancer (seven synchronous, 12 metachronous). The median age at diagnosis of first colorectal cancer was 47 years (range 33-74 years). Cancers occurred in the context of a few adenomas (< 10). The majority of patients (n = 108) had surgery as the first line management. One patient received palliative care. Twenty-five patients had endoscopic surveillance as first line management; no cancers occurred in this group. Patients who had segmental resection and postoperative surveillance still appeared to be at risk of metachronous cancer (5/30, 17%). CONCLUSIONS: MUTYH testing should be considered even in the context of cancers occurring with fewer than 10 adenomas. In cases of primary colorectal cancers, extended surgery should be considered if patients do not have access to high quality endoscopic surveillance postoperatively. For some patients, endoscopic therapy is an appropriate and safe option in expert hands.

Session 3: Beyond the boundaries of Total Mesorectal Excision - where surgeons fear to tread.

Approximately 10-15% of patients present with an advanced rectal cancer that extends beyond the conventional total mesorectal excision (TME) planes. In such cases extending the surgery to ensure resection with clear margins (R0 resection) is essential in order to achieve long-term cure. Professor Holm describes the techniques of beyond-TME exenterative surgery, the methods of patient selection and outcomes.

Session 3: Intra-operative radiotherapy - creating new surgical boundaries.

In patients with advanced and recurrent colorectal cancer, surgical resection with clear margins is the greatest challenge and is limited by known anatomical constraints. Preoperative or intra-operative assessment of the limits of surgical dissection may help to explore the possibility of improving resectability through either targeted external beam radiotherapy or intra-operative radiotherapy. Professor Chang reviews the evidence base and potential advantages and disadvantages of this approach, whilst the expert panel agree a consensus on the evidence for assessment and therapy of such patients.

Roles for FGF in lamprey pharyngeal pouch formation and skeletogenesis highlight ancestral functions in the vertebrate head.

A defining feature of vertebrates (craniates) is a pronounced head supported and protected by a cellularized endoskeleton. In jawed vertebrates (gnathostomes), the head skeleton is made of rigid three-dimensional elements connected by joints. By contrast, the head skeleton of modern jawless vertebrates (agnathans) consists of thin rods of flexible cellular cartilage, a condition thought to reflect the ancestral vertebrate state. To better understand the origin and evolution of the gnathostome head skeleton, we have been analyzing head skeleton development in the agnathan, lamprey. The fibroblast growth factors FGF3 and FGF8 have various roles during head development in jawed vertebrates, including pharyngeal pouch morphogenesis, patterning of the oral skeleton and chondrogenesis. We isolated lamprey homologs of FGF3, FGF8 and FGF receptors and asked whether these functions are ancestral features of vertebrate development or gnathostome novelties. Using gene expression and pharmacological agents, we found that proper formation of the lamprey head skeleton requires two phases of FGF signaling: an early phase during which FGFs drive pharyngeal pouch formation, and a later phase when they directly regulate skeletal differentiation and patterning. In the context of gene expression and functional studies in gnathostomes, our results suggest that these roles for FGFs arose in the first vertebrates and that the evolution of the jaw and gnathostome cellular cartilage was driven by changes developmentally downstream from pharyngeal FGF signaling.

Interventional stem cell therapy.

The ability to deliver cells in appropriate doses to their targeted site of action is a well-known obstacle to optimising stem cell therapy. Systemic administration of cells results in pulmonary "trapping," which significantly decreases the number of available circulating cells to impact underlying disorders. Directed delivery of stem cells in interventional radiology may provide an additional option for bypassing the lungs, as well as introduce novel potential avenues for decreasing doses required to effect cellular therapy, efficiently obtain local paracrine effects, and/or to simplify targeting strategies.

Health literacy: applying current concepts to improve health services and reduce health inequalities.

The concept of 'health literacy' refers to the personal and relational factors that affect a person's ability to acquire, understand and use information about health and health services. For many years, efforts in the development of the concept of health literacy exceeded the development of measurement tools and interventions. Furthermore, the discourse about and development of health literacy in public health and in clinical settings were often substantially different. This paper provides an update about recently developed approaches to measurement that assess health literacy strengths and limitations of individuals and of groups across multiple aspects of health literacy. This advancement in measurement now allows diagnostic and problem-solving approaches to developing responses to identified strengths and limitations. In this paper, we consider how such an approach can be applied across the diverse range of settings in which health literacy has been applied. In particular, we consider some approaches to applying health literacy in the daily practice of health-service providers in many settings, and how new insights and tools--including approaches based on an understanding of diversity of health literacy needs in a target community--can contribute to improvements in practice. Finally, we present a model that attempts to integrate the concept of health literacy with concepts that are often considered to overlap with it. With careful consideration of the distinctions between prevailing concepts, health literacy can be used to complement many fields from individual patient care to community-level development, and from improving compliance to empowering individuals and communities.

Effect of a novel sterilization method on biomechanical properties of soft tissue allografts.

PURPOSE: Evaluate allograft tissue commonly used in soft tissue reconstruction to determine whether stiffness and strength were significantly altered after grafts were treated with different sterilization methods. Unprocessed, irradiated, and grafts treated with supercritical CO2 were compared. METHODS: Thirty-eight anterior or posterior tibialis tendons were obtained from a tissue bank (Allograft Innovations, Gainesville, FL). Group I was unprocessed, group II was sterilized with gamma irradiation (20-28 kGy), and group III was sterilized with supercritical CO2. The grafts were pretensioned to 89 N for 300 s. Specimens were then loaded from 50 to 300 N at 0.5 Hz for 250 cycles before being loaded to failure at 50 mm/min. Dependent variables were compared between sterilization groups with one-way ANOVA (P < 0.05) and equivalence trial. RESULTS: There was no significant difference in load to failure or failure stress among groups I, II, and III. Group III resulted in 27-36 % lower stiffness than group I and II. This difference was significant at 1, 10, 50, 100, and 250 cycles. There was no significant difference in stiffness between group I and group II. CONCLUSION: The two sterilization methods tested in this study do not affect allograft strength. The supercritical CO2 sterilization method resulted in significantly lower stiffness than unprocessed and irradiated allografts. However, the stiffness and strength of all groups tested were greater than that of published values of the native intact anterior cruciate ligament (ACL). This study provides previously unpublished mechanical test data on a new sterilization technique that will assist surgeons to decide which allograft to use in ACL reconstruction surgery. LEVEL OF EVIDENCE: III.

Long-term adverse outcomes in survivors of childhood bone sarcoma: the British Childhood Cancer Survivor Study.

BACKGROUND: With improved survival, more bone sarcoma survivors are approaching middle age making it crucial to investigate the late effects of their cancer and its treatment. We investigated the long-term risks of adverse outcomes among 5-year bone sarcoma survivors within the British Childhood Cancer Survivor Study. METHODS: Cause-specific mortality and risk of subsequent primary neoplasms (SPNs) were investigated for 664 bone sarcoma survivors. Use of health services, health and marital status, alcohol and smoking habits, and educational qualifications were investigated for survivors who completed a questionnaire. RESULTS: Survivors were seven times more likely to experience all-cause mortality than expected, and there were substantial differences in risk depending on tumour type. Beyond 25 years follow-up the risk of dying from all-causes was comparable to the general population. This is in contrast to dying before 25 years where the risk was 12.7-fold that expected. Survivors were also four times more likely to develop a SPN than expected, where the excess was restricted to 5-24 years post diagnosis. Increased health-care usage and poor health status were also found. Nonetheless, for some psychosocial outcomes survivors were better off than expected. CONCLUSIONS: Up to 25 years after 5-year survival, bone sarcoma survivors are at substantial risk of death and SPNs, but this is greatly reduced thereafter. As 95% of all excess deaths before 25 years follow-up were due to recurrences and SPNs, increased monitoring of survivors could prevent mortality. Furthermore, bone and breast SPNs should be a particular concern. Since there are variations in the magnitude of excess risk depending on the specific adverse outcome under investigation and whether the survivors were initially diagnosed with osteosarcoma or Ewing sarcoma, risks need to be assessed in relation to these factors. These findings should provide useful evidence for risk stratification and updating clinical follow-up guidelines.

A pregnancy lifestyle intervention to prevent gestational diabetes risk factors in overweight Hispanic women: a feasibility randomized controlled trial.

AIMS: To pilot the feasibility of a prenatal lifestyle intervention to modify physical activity and diet among pregnant overweight and obese Hispanic women, with the aim of reducing risk factors for gestational diabetes mellitus. METHODS: Women were randomized either to a lifestyle intervention (n = 33, 48.5%), consisting of a culturally and linguistically modified, motivationally targeted, individually tailored 6-month prenatal programme, or to standard care (n = 35, 51.5%). Bilingual and bicultural health educators encouraged women to achieve guidelines for physical activity, decrease saturated fat and increase dietary fibre. Outcomes included gestational weight gain, infant birth weight and biomarkers associated with insulin resistance. RESULTS: Patient retention up to delivery was 97% in both study groups. The lifestyle intervention attenuated the pregnancy-associated decline in moderate-intensity physical activity, but differences between groups were not significant (mean ± se -23.4 ± 16.6 vs -27.0 ± 16.2 metabolic equivalent of task h/week; P = 0.88). Vigorous-intensity activity increased during the course of pregnancy in the lifestyle intervention group (mean ± se 1.6 ± 0.8 metabolic equivalent of task h/week) and declined in the standard care group (-0.8 ± 0.8 metabolic equivalent of task h/week; P = 0.04). The lifestyle intervention group also had slightly lower gestational weight gain and infant birth weights compared with the standard care group; however, these differences were not statistically significant. There were no statistically significant differences in biomarkers of insulin resistance between groups. CONCLUSIONS: Findings suggest that a motivationally matched lifestyle intervention is feasible and may help attenuate pregnancy-related decreases in vigorous physical activity in a population of overweight and obese Hispanic women. The intervention protocol can readily be translated into clinical practice in underserved and minority populations.

Ongoing challenges responding to behavioural and psychological symptoms of dementia.

BACKGROUND: Mid- to late-stage dementia is often characterized by behavioural and psychological symptoms, including, but not limited to physical and verbal aggression. INTRODUCTION: Although there is a considerable research about the prevalence, aetiology, and management of behavioural and psychological symptoms of dementia, there is limited research about the experience of caring for people with such symptoms in long-term aged care facilities. AIM: The aims of the study were to describe: (i) nurses' experiences of caring for people with behavioural and psychological symptoms of dementia in long-term aged care facilities, and (ii) strategies nurses used to deal with these symptoms. METHODS: A qualitative exploratory and descriptive design, involving focus group interviews with 30 nurses from three long-term aged care units in Australia. The transcripts were analysed using inductive content analysis. RESULTS: The findings revealed five interrelated themes: (i) working under difficult conditions, (ii) behavioural and psychological symptoms of dementia: an everyday encounter, (iii) making sense of behavioural and psychological symptoms of dementia, (iv) attempting to manage behavioural and psychological symptoms of dementia, and (v) feeling undervalued. CONCLUSION: This study highlighted the difficult conditions under which nurses worked and the complexity of caring for individuals who have behavioural and psychological symptoms of dementia. IMPLICATIONS FOR NURSING AND HEALTH POLICY: Organizational efforts to enhance the quality of care for individuals with behavioural and psychological symptoms of dementia in long-term aged care facilities should extend beyond staff education to heed nurses' concerns about organizational barriers to interpersonal care.

Breast cancer risk after radiotherapy for heritable and non-heritable retinoblastoma: a US-UK study.

BACKGROUND: Retinoblastoma is a rare childhood eye cancer caused by germline or somatic mutations in the RB1 gene. Previous studies observed elevated breast cancer risk among retinoblastoma survivors. However, there has been no research on breast cancer risk in relation to radiation (primarily scatter radiation from the primary treatment) and genetic susceptibility of retinoblastoma survivors. METHODS: Two groups of retinoblastoma survivors from the US and UK were selected, and breast cancer risk analysed using a case-control methodology, nesting within the respective cohorts, matching on heritability (that is to say, having bilateral retinoblastoma or being unilateral cases with at least one relative with retinoblastoma), and using exact statistical methods. There were a total of 31 cases and 77 controls. RESULTS: Overall there was no significant variation of breast cancer risk with dose (P>0.5). However, there was a pronounced and significant (P=0.047) increase in the risk of breast cancer with increasing radiation dose for non-heritable retinoblastoma patients and a slight and borderline significant (P=0.072) decrease in risk of breast cancer with increasing radiation dose for heritable retinoblastoma patients, implying significant (P=0.024) heterogeneity in radiation risk between the heritable and non-heritable retinoblastoma groups; this was unaffected by the blindness status. There was no significant effect of any type of alkylating-agent chemotherapy on breast cancer risk (P>0.5). CONCLUSIONS: There is significant radiation-related risk of breast cancer for non-heritable retinoblastoma survivors but no excess risk for heritable retinoblastoma survivors, and no significant risk overall. However, these results are based on very small numbers of cases; therefore, they must be interpreted with caution.

EVOLUTIONARY CO-OPTION OF AN ANCESTRAL CLOACAL REGULATORY LANDSCAPE DURING THE EMERGENCE OF DIGITS AND GENITALS.

The transition from fins to limbs has been a rich source of discussion for more than a century. One open and important issue is understanding how the mechanisms that pattern digits arose during vertebrate evolution. In this context, the analysis of Hox gene expression and functions to infer evolutionary scenarios has been a productive approach to explain the changes in organ formation, particularly in limbs. In tetrapods, the transcription of Hoxd genes in developing digits depends on a well-characterized set of enhancers forming a large regulatory landscape1,2. This control system has a syntenic counterpart in zebrafish, even though they lack bona fide digits, suggestive of deep homology3 between distal fin and limb developmental mechanisms. We tested the global function of this landscape to assess ancestry and source of limb and fin variation. In contrast to results in mice, we show here that the deletion of the homologous control region in zebrafish has a limited effect on the transcription of hoxd genes during fin development. However, it fully abrogates hoxd expression within the developing cloaca, an ancestral structure related to the mammalian urogenital sinus. We show that similar to the limb, Hoxd gene function in the urogenital sinus of the mouse also depends on enhancers located in this same genomic domain. Thus, we conclude that the current regulation underlying Hoxd gene expression in distal limbs was co-opted in tetrapods from a preexisting cloacal program. The orthologous chromatin domain in fishes may illustrate a rudimentary or partial step in this evolutionary co-option.

Second and subsequent tumours among 1927 retinoblastoma patients diagnosed in Britain 1951-2004.

BACKGROUND: Retinoblastoma is an eye tumour of childhood that occurs in heritable and non-heritable forms. In the heritable form, there is a predisposition to the development of non-ocular subsequent primary tumours (SPTs). METHODS: This study included 1927 retinoblastoma patients diagnosed in Britain from 1951 to 2004. Ascertainment was through the (UK) National Registry of Childhood Tumours; cases were followed-up for the occurrence of SPTs. Standardised incidence ratios (SIRs) were calculated. RESULTS: We identified 169 SPTs in 152 patients. The SIR analysis included 145 SPTs with cancer registrations from the years 1971 to 2009. These tumours occurred in 132 patients: 112 of the 781 heritable and 20 of the 1075 (presumed) non-heritable cases under surveillance at the start of this period developed at least one registered SPT. The SIRs for all tumours combined were 13.7 (95% confidence interval 11.3-16.5) in heritable cases and 1.5 (0.9-2.3) in non-heritable cases. The main types of SPT in the heritable cases were leiomyosarcoma, (31 cases; SIR 1018.7 (692.2-1446.0)), osteosarcoma (26 cases; SIR 444.6 (290.4-651.4)), and skin melanoma (12 cases; SIR 18.6 (9.6-32.4)). CONCLUSION: The risk of SPTs in heritable retinoblastoma is extremely high. This has important implications for the clinical follow-up and counselling of survivors and their families.